(Updates toll, adds quotes and background)
By Hadeel Al Shalchi
BENGHAZI, Libya, July 6 (Reuters) - A helicopter carrying voting material for Saturday's election in Libya made a forced landing near the eastern town of Benghazi on Friday after being struck by anti-aircraft fire in an attack which killed one person on board, a local official said.
It was the latest attempt to derail elections in a region where many seek more autonomy and argue they will be under-represented in a new assembly that will name a prime minister and pave the way for full parliamentary polls next year.
"We were preparing to receive the voting material as it arrived on a helicopter from Tripoli but it was hit and one man died," Ahmed Abdelmalik, an employee at the local branch of the election commission told Reuters.
Hamed Al-Hassi, head of the military council for the Cyrenaica region, confirmed the incident but said the identity of the attackers was not immediately known.
Protests by groups seeking greater autonomy in the east earlier forced the closure of three ports, shutting down around half of Libya's oil exporting capacity.
On Thursday, the main storage centre for election materials in the eastern town of Ajdabiya was badly damaged in a suspected arson attack.
The elections are Libya's first free national vote in over half a century and come barely a year after the ousting of Muammar Gaddafi by a NATO-backed uprising. Regional and tribal loyalties suppressed under Gaddafi have since come to the fore.
"We expected this issue," Emad El-Sayih, deputy head of Libya's High National Election Commission (HNEC), told Reuters.
"There is no security in this country - the interior ministry and the army are incapable of protecting the elections. The (election) commission is in a state of depression." (Additional reporting by Ali Shuaib in Tripoli; Writing by Mark John; Editing by Andrew Osborn)